The use of buildings having rigid metallic frames covered with sheet metal roof and wall panels has become widespread, and efforts have been made at thermally insulating such metallic buildings. The method of insulation in common use involves fixing a thick layer of insulating material, such as glass wool, onto the inner surfaces of the sheet metal roof and wall panels before they are secured to the metallic columns, beams braces and rafters comprising the rigid frame of the building. The wall panels are commonly secured in place by bolts or rivets, and the layer of insulating material is compressed and pinched between the panels and the rigid frame by the fasteners.
While this common method of insulation is generally known and used, problems exist. There is first of all a significant, prejudicial heat loss which occurs because of the metal-to-metal contact between the sheet metal panels, the rigid metallic frame, and the metallic fasteners used to secure the panels to the rigid frame. The metallic fasteners in effect provide a permanent thermal conduit between the interior and the exterior of the building, since they are good thermic conductors, and the pinching of the layer of insulating material between the rigid frame and the panels caused by the presence of the fasteners contributes to the thermal flow.
Further, there is at present a condensate problem found in many such buildings, again resulting from the metal-to-metal contact required in their construction. The formation of condensate will sometimes occur on substantially every part of the rigid metallic frame, which is maintained in thermal contact with the exterior sheet metal roof and wall panels by the metallic fasteners. This condensation can cause problems for the occupants and usage of the building, and is undesirable.
The loss of heat from such rigid frame metallic buildings, even when insulated in the manner noted, is a known problem. The heat loss occurs by both conduction and convexion, and is obviously prejudicial to efficient energy use. The accompanying problem of moisture condensation on the rigid metallic frame within the building is also prejudicial for the obvious reasons. Efforts to overcome these two problems have been undertaken in the past, and have included increasing the thickness of the insulation layer applied to the roof and wall panels, and the insertion of a reflective foil between the panels and the insulation. However, the problems have remained.
There is thus need for a method of insulating such rigid frame metallic buildings so as to prevent excessive heat loss, and to alleviate the formation of moisture condensate on the parts of the rigid frame. The present invention is directed toward meeting that need.